The families of the Pike River victims have come to parliament to present their case for re-entering the mine where 29 men were killed in 2010.
They'll be in front of the commerce select committee today, armed with a report from experts who believe it's safe to re-enter the mine's drift, the tunnel that leads into it.
State-owned Solid Energy, which owns the mine, considers it isn't safe to re-enter and had intended putting a final seal in place.
Prime Minister Bill English, after meeting the family representatives, ordered a halt to the work yesterday.
He has ruled out sending people into the drift, but wants Solid Energy to investigate using robot equipment to look inside it.
The families believe there may be evidence in the drift which could answer some of the questions around what caused the methane explosions that killed their loved ones.
They also hope it may be possible to retrieve remains.
Their spokesman, Bernie Monk, will lead the delegation at the select committee hearing.
With him will be Tony Forster, a former Worksafe chief mines inspector who supports their cause.
They will give MPs on the committee a report by mining engineers Robert Stevenson and David Creedy which outlines a case for safe re-entry.
The families have for months been picketing the West Coast mine in a bid to stop the sealing work that Mr English has halted.
Mr Monk says the pickets will leave now that there's been "a positive step" from the government.